Question

Read the given statements and conclusions carefully. Assuming that the information given in the statements is true, even if it appears to be at variance with commonly known facts, decide which of the given conclusions logically follow(s) from the statements.

Statements:

All gabions are walls.

All concretes are walls.

All bridges are walls.

Conclusions:

(I) Some bridges are gabions.

(II) Some concretes are bridges.

• A. Neither conclusion (I) nor (II) follows
• B. Only conclusion (I) follows
• C. Both conclusions (I) and (II) follow
• D. Only conclusion (II) follows

Answer 1

Answer:

A. Neither conclusion (I) nor (II) follows

Syllogism Analysis: Statements and Conclusions

Understanding the Premises

• Statement 1: All gabions are walls. This means the set of 'gabions' is entirely contained within the set of 'walls'.
• Statement 2: All concretes are walls. Similarly, the set of 'concretes' is entirely contained within the set of 'walls'.
• Statement 3: All bridges are walls. This indicates that the set of 'bridges' is also entirely contained within the set of 'walls'.

Analyzing the Conclusions

• Conclusion I: Some bridges are gabions.
• The statements establish that both 'bridges' and 'gabions' are subsets of 'walls'.
• However, there is no information given to suggest any overlap or relationship between the set of 'bridges' and the set of 'gabions'. They could be separate subsets within 'walls', or they could partially or fully overlap.
• Without a direct link or a common subset defined between bridges and gabions, this conclusion cannot be logically derived.
• Conclusion II: Some concretes are bridges.
• Similar to Conclusion I, 'concretes' and 'bridges' are both stated to be subsets of 'walls'.
• There is no information provided that indicates any intersection between the set of 'concretes' and the set of 'bridges'.
• Therefore, we cannot conclude that some concretes are bridges based solely on the given statements.

Logical Derivation

• The given statements place gabions, concretes, and bridges as distinct categories within the larger category of walls.
• However, these categories (gabions, concretes, bridges) might be mutually exclusive, partially overlapping, or one might be a subset of another within the 'walls' category, but the statements do not provide this information.
• In syllogistic reasoning, a conclusion is valid only if it *must* be true given the premises. In this case, the conclusions are possible but not necessary.
• Therefore, neither conclusion logically follows from the given statements.